System for producing modulated waves



Nov. 13,1923. "Re-15.122

. R. A. HEISING SYSTEM FOR PRODUCING MODULATED WAVES Reissued Nov. 13, 1923.

UNITED! srATEs PATENT OFFICE.

mom: a. nnisrNo, or mIL noaN,.-.Ni:w JERSEY, ASSIGNOR 'ro wEs'rnnN amic- 'TBIC COMPANY, INcoaronA'rEn, or NEW YORK, N; 2., A CQRPOBATION or new xoax."

srs'rmr Fox riionociNc monona'rnn, wavas.

Original Il'o. 1,438,262, dated November 21, 1922 Serial No.'268,469, filed-December 27, 1918. Application for reissue filed August 8, 1928. Serial Ho; 656,436. i

'1 '0 all whom it mm concern: I 1

Be it known that RAYMOND A.'Hnis'INo, a citizen of the United States of America,

' residing atMillburn, in the county of Essex and State of New Jerse have invented certain new and useful mprovements in Systems for Producing Modulated Waves, of which the following is a full, clear, concise, and exact description. 1

This invention relates to the production of modulated high frequency electromagnetic waves by varying the current or voltage supplied to an arcin accordance" with signa'lsyfor example, sound signals.

Objects of the invention are: vide signaling means wherein transmission is produced by uniformly recurring discharges of amounts of electricity which vary.

in accordance with signals: (2) To prov-ide such means which are adated for the transmission/of speech: (3) 0 provide systems in which large currents, modulated in accordance with ma be efiiciently generated by an are a" (4) 'in which the frequency of arc discharges is maintained constant independently of variations in their. amplitude: (5) 0 provide efficient variable impedance means for assoeiating a microphone or equivalent with an arc generator in high frequency signaling systems.

Consideration of the following description will suggest other objects and advanta es of the invent-ion.

e variation in voltage of the current supplied to the arc is caused by a variable impedance either in shunt to, in series with the are or otherwise suitably relate'd'thereto. The-variable impedance preferably consists of a device of the electron discharge type. For telephony the discharge device is controlled b a microphone ore uivalent element. se is made of a thir or auxiliary electrode of the are for controlling the main arc discharge. By adjusting the constants inthe a-uxiliaryelectrode circuit, the frequency can be controlled .inde rid.- ently, in a large degree, of the amp itude variation due to the signals.

For more definite explanation of the invention, reference is made to the accompanying drawings wherein Fig. li-ep'resents v a system having a discharge device in series char e device'in paralle (1) To pro- 0 "provide systems with an arc; Fig. 2 a system having a diswithan arc; Figs." 3 an 4 are other modified forms, while Fig. 5 discloses an arrangement which may be utilized in connection with any of the precedin arrangements.

' Re e-rring particularly; to Fig. 1, a generator 5 COIlStltlltCS a source of direct current for supplying an arc circuit which comprises the anode-cathode path of the electron discharge device 6, the high frequency choke coil 7, the electrode 8, electrode 9 and conductors 10 and 11. ,The device 6 typifies either asingle vacuum tube or a suitable system of such tubes in parallel or series relation. The material of which the electrodes 8 and. 9 are composed, the space therebetween, and the maximum voltage across the electrodes, are so" chosen that normally the discharge will not occur except as it is controlled, triggered, primed or tripped off .by the discharge across the electrodes 12 and 9. The frequency of the discharges across electrodes 9 and 12 is controlled by the magnitudes of inductance 13 and capacity 14in the control circuit 15, which circuit includes electrodes 12 and 9. The control circuit is energized by the source 5but it is optional 13?) provide a separate control source. The elec- "tromagnet 17 maintains a field across the space between electrodes 8, 12 and 9 which serves to extinguish the are after each discharge. The magnet 17 is ener ized by source 5' but it is optional to provi e a separate source asshown in Fig. 4:. The'device .6 includes an anode 18, a filamentary cathode series with the controlling microphoneor an equivalent device 26 in the circuit 25. The usual sources 27 and 28 areprovided for heating the cathode and maintaining the grid ne 'ative with respect thereto respectively. he arc across the electrodes Sand 9 is included in the path to ground of the antenna circuit which com rises inductance 29 and the serial 30. Wit pro r adjustmentsthe radiated fr uency wil be an approximate sine wave 0 thesame frequency as the frequency of the discharges across electrodes 9 and 12.- I

Fig. 2 shows an arrangement in which the discharge device 6 is located in parallel instead of in series with the arc electrodes 8 and 9. Low frequency variations of voltage across device 6, due to the action of microphone 26, will cause negligible change of current through coil 31, due toits high of direct current, such as a generator 33 or a battery. Coil 32 is coupled to coil 34 which thereby serves to impress low frequency variations of voltage across the path comprising the arc electrodes 8 and 9 which correspond to variations across the anodecathode circuit of device 6. Coil 7 serves to prevent the shunting of high frequency oscillations around the arc to ground. This. arrangement differs from that of Fig. 1-

in that the device 6, instead of being in series with the current supply path of the arc is coupled to this path by means of a transformer 32, 34L.

In Fi 4 the device 6, instead of being in a pat parallel to the arc supply circuit,

as in Fig. 2, is coupled by means of transformer 35, 36 to a shunt path 37 which comprises capacity 38 and secondary 36. The microphone acts upon device 6to vary the space current therethrough, and these variations in turn cause corresponding voltages to be ,induced in path 37. The electromagnet 17 may be supplied by a separate source 38'. The control circuit may also be energized by separate source 5 in series with which an inductance 40 may be placed, if necessary.

The function of those elements of Figs. 2, 3 and 4 which are not given in detail, may be readily understood by reference to the description of the correspondingly numbered elements of Fig. 1.

Fig.5 illustrates a modified arrangement which may be.utilized in connection with any of the preceding. The main oscillation circuit 29, 30 is here substituted for -tion .of harmonic frequencies.

the antenna circuit of the precedin fig-- ures. The antenna circuit 39 is coupiad to the oscillation circuit by coil 29. By means of this arrangement the oscillations existing in the antenna will have a smaller propor- Intermediate tuned circuits may be placed between .the oscillation circuit and the antenna 39 t0 more effectively eliminate the harmonics. Such tuned circuits are well known and therefore [need no description. By substitu-tinga transmission line for the antenna,

constant.

this invention may be utilized fortrans- .mitting intelligence over conductive circuits.

Operation: The generator 5 supplies a direct voltage to the circuit 15 and condenser 14 which periodically discharges across the electrodes 9 and 12 arid causes simultaneous discharge across the electrodes 8 and 9. The amplitude of the discharge across the electrodes 8 and 9., will depend largely upon the instantaneous-condition of the device 6. Thus while the amplitude of the discharge may be made to vary, the frequency thereof will remain substantially Although the discharge across electrodes 9, 12 may consist of a small amount of ener it may serve to control the discharge 0? much larger amount of energy across'the electrodes 8, 9. The device 6 acts as an amplifier and reproduces inamplified form the impedance changes in or the current changes through the device 26. The antenna capacity or the equivalent capacity 30 is continually being charged'by the source 5, but the rate of charge varies in accordance with the condition of device 6.

Novel features inherent in the invention are defined in the appended claims.

What is claimed is:

1. -A system comprising an arc generator, a direct current supply source for said generator, means for varying in" accordance with sound waves the potential supplied by said source at a rate lower than the frequency generated by said generator, and means to prevent the operation of said firstmentioned means from materially changing the frequency generated by said generator.

2. A system comprising an arc generator, a direct current supply source therefor, and a non-periodic path including a signal con trolled discharge device in shunt. to said generator for varying at a low frequency rate the potential supplied by said source.

3. A system comprising an arc generator, a direct current energy source therefor, and an untuned path including a dischage device for shunting. from said generator in accordance with sound waves the energy supplied by said source.

a 4. A system comprising an arc generator, a direct current supply source therefor, a discharge device for varying in accordance with electrical waves representing human speech the effective potential supplied by said source, and means to prevent the operation of said discharge device from materially changing the base frequency generated.

5. A system comprising a source of electric' current, an arc device for transforming the energy from quenc alternating energy, a discharge device or controllin the instantaneous voltage supplied bysaid source, and a common said source into high fre- .alternating current whose amp source of constant current for supplying said devices.

6. A system comprising a source of electric current, an are for transforming the energy from said source into high frequency itude is dependent upon the instantaneous magnitude of the voltage supplied b said source, a

. dischar e device for contro ling the voltage supplie by said source and means for supplying said device with current from said source. a

7. A system comprising an are for transforming electrical energy into high fre-' quency alternating current energy, an energy supply for said arc varying at a si mlin frequency, and means'operable wit out su stantial time lag for preventing variations'in said energy supply from affecting the frequency generated bysaid are.

8. A system comprising an are for transforming electrical current energy into hi h frequency oscillations, a current supp y source for said arc, a speech controlled electric device for varying the current supply ofsaid arc, and means operable with a time lag measurably less than the period of an audible sound wave for preventing variations in the current'supply from "aryin'g the period of said oscillations.

9. A system for generating modulated high frequency waves, comprising an arc generator, a current supply source therefor, means adapted to bevvaried at a rate Within the range of audibility for varying the cur,- rent supplied from said source, and means? for preventing variations at said rate .inZ

--said current supply from varying the fre;

quency of said generator.

10. A stem comprisin a main oscillation circuit, an arc device or generating 0'scillations in said circuit, current supply 7 means for said are device, means adapted to be controlled in accordance with sound signals for varying the current supplied from said source, a control circuit for said are, and means associating said circuit with said are whereby the tendency of signaling variations in. current supply to said are to change the frequency of oscillations is counteracted.

11. A system comprisin a main oscilla-' tioncircuit, an arc device or generating'oscillations in said circuit, .a current supply means for said-arc device, an "electron discharge device for varying the current supplied from said means, and atrigger control circuit including inductance and capacity for "said are. I

- 12. A system comprising a, source of dis rect current,- an arc, and an electron dis-- charge device, said are and said. discharge device being in paths conductive to. directcurrent which are in parallel with; respect .to id source;

1 A system compris ng a source of enerizing current, an are, an electron discharge evice, and'means for varying the impedanoe of said discharge device, said are and said discharge device being in paths conductive to direct current which are in parallel with respect to said source.

14, A system comprisin a source-cot direct current, an are, an e ectron discharge device, said are and said discharge device bein in paths conductive to direct current whic are'in parallel with respect to said source, and means to maintain the current throu h said source substantially constant.

15. n combination, a source of substantially constant current, an arc, and an elec tron discharge device, said are and said de vice being in paths conductive to direct 'current which are in parallel with respect to said-source.

16. A system comprising an arc, an electron discharge device, the terminals of said are and said device being connected by conduotorsof negligible impedance for direct and speech frequency current, and a common source of e ectrical energy for) supplying, current to said are and said device. '17.A system comprising a source of direct current, a speech frequency choke coil, a high frequencychoke coilfand main arc electrodes, said aforementioned elements being located ina series circuit, a conductive .path shunted across the high frequency choke coil and the arc, an electron discliar e device operatively associated with said pat 1, means including a microphone and an input circuit for controllin "the impedance of said device, a high irequency osciila-tion capacity shunted around'said source of direct current, an auxiliar electrode for said are, one portion of sai control circuit being connected to one of said main electrodes and another portion to said auxiliary electrode, and means for maintaining a magnetic field across the space between said main and auxiliary electrodes.

device having ananode, 'an'electr'on emitting'cathodeand an impedance controlling element,'said arc and said device being in non-periodic paths which are in parallel with respect to said source.

- 19'. A system comprising a source of'current, means to vary thevoltage supplied by. said source at a low frequency rate, a dis charge path for said source, and means operating independently of discharges across said path to cause discharges across said path at a high frequency rate which is substantially in e ndent' of the instantaneous volta supp ied by said source.

I 20. In com ination, an arc, means for impressingthereon an electric potential varycircuit shunted around s'a-id electrodes, :1 -control circuit including inductance and 18..-A systemcomprising an arc, a source of current therefor, ane ectron discharge ing in accordance with signals, means for extinguishing said arc, and means for priming said arc at a constant frequency rate.

21. The method of producing modulated oscillations in a+circuit which comprises charging a capacity in the circuit, varying at a low frequency rate the charging current for said capacity, and causing the dischar e of the capacity at a constant and relative? high rate. v

22. The method which comprises causing a current to continuously fiow to charge a capacity, varying the amperage of said current in accordance with speech, and periodically priming a discharge path to cause the ca city to discharge therethi'ougli at a frequency which is high as compared with. speech frequencies. y 23. The method which comprises forcing a continuous current into a capacity, varying the rate of flow of the current at a comparatively low frequency, and priming a discharge path to cause the capacity to discharge therethroi'igh at a radio frequency rate.

24. The method which comprises forcing a continuous current into a capacity vari ably impeding a shunt path aroundsaid capacity at a comparatively low frequency and discliargingtlie capacity at a constant and relatively high. frequency rate.

25. A systcmcomprising an arc, a source of current-therefor. highly evacuated unidirectionally conducting electron discharge dcvice, an anode-cathode discharge path within said device, and means for varying the impedance of said path, said are and said path being in paths conductive to direct currentwhich are in parallel with respect to said source.

2G. The method of operating a system comprising an arc and a space discharge device having an anode-cathode path, with means for controlling the impedance of said path, which comprises maintaining constant the sum of the currents through said are and said device. A I

,27. A system comprising an arc device, a

2 "space discharge device having-[an anode and an electron emitting cathodecomprising ter: minals of a discharge path, a common source of electrical energy for said path and said arc. and means for varyingthe current to said are by variably dissipating energ in said device.

28. A system comprising -an arc, a space discharge device having an anode and an electron emitting cathode comprising terminals of a discharge path, means for ener gizing said cathode, a common source of current for said are and device, and means for preventing variations in current supply from said source.

29. An are system having main electrodes and neans for impressing a variable voltage thereacross, an auxiliary electrode, a primmg circuit connected to said auxiliary electrode, and a steady current supply for said priming circuit, said priming circuit and auxiliary electrodeheing arranged to prime said-arc at regular intervals irrespective of voltage variations across said main'electrodes.

30. In a constant frequency arc system, the combination of an oscillation circuit containing a normally inoperative arc gap, a trigger oscillation circuit containing a normally operative arc gap for priming said first mentioned arc gap,.means for energizing said circuits, and means for producing a magnetic field across said gaps.

2-51. In a signaling system, a main oscillation circuit containing a normally inoperative arc gap, a trigger oscillation circuit containing -a normally operative arc gap for priming said first mentioned arc gap. means for-tuning said circuits to the same carrier frequency, means for energizing said circuits, means for producing a magnetic field across said gaps, and a load circuit associated with said main oscillating circuit.

32., In constant frequency oscillating system, '1? 1e combination of an oscillation circuit containing two electrodes, a second oscillation circuit containing one of said electrodes and a third electrode, means for producing a magneticfield in the space occupied by said electrodes, means for ener-- gizing said circuits,- and translating means associated with-oneof said circuits.

33. In a .constant frequency oscillating systemdthecombination of a main oscillation circuit containing an anode and a cathode, a trigger oscillation circuit containing said cathode and a. second anode, said circuits also including means for tuning said circuits to substantially the same carrier frequency, means for energizing said circuits, means for. producing a magnetic field acrossthe gaps formed by said anodes and cathodes, and means for takin constant frequency oscillations from sai main oscillation circuit. 4

34. In an oscillation generating system, a power generator'of oscillations including an electric sace discharge device having fixed electro es, an oscillating system ineluding an electric s ace discharge device- .having fixed electro es, means for maintaining the oscillations-of said power generator. n frequency synchronism with said oscillating system, and an energy consumption circuit said power generator being coupled to said energy consumption circuit and said oscillating system being more remotely associated with said energy consumption circuit through saidpower generator.

35. In combination, an energy storing,

circuit,means for char ing said circuit, a discharge path for sai circuit Whose impedance is normally so great as to prevent discharge therethrough, a control circuit for said discharge path, means for charging said control circuit t a substantially uniform rate, a discharge path for said control circuit operative only when said circuit is charged to a predetermined degree, and means so associating said circuits that discharge of the control circuit lowers the inipedance of the discharge path of the energy storing circuit to the discharging point.

36. An oscillation generator comprising an oscillating arc circuit having a constant natural period, an oscillating arc circuit having a variable natural period, and means for producing oscillations in said second circuit of constant frequency controlled by said first circuit.

37. A system for generating oscillations of constant carrier frequency and modulating the oscillations in accordance with a variable signal wave which comprises an oscillating arc circuit having a constant natural period, an oscillating arc circuit having a period which tends to vary as the signal Wave varies, and means for producing oscillations in said second circuit of substantially constant frequency controlled by the first circuit.

In witness whereof I hereunto subscribe my name this 30th day of July, A. D. 1923.

- -RAYMOND'A. HEISING. 

